This change adds low-level support for TLS handshake timeouts in the
class that actually performs the handshake. The contractual
`socketTimeout`, if set, will only be applied to the underlying
IOSession after the handshake is complete.

- Deprecate and rename org.apache.hc.core5.util.Timeout.ofMillis(long)
to ofMilliseconds(long).
- Deprecate and rename org.apache.hc.core5.util.TimeValue.ofMillis(long)
to ofMilliseconds(long).
- In both cases, this was the only abbreviated API name in that class.
For comparison, we use ofMicroseconds(), not ofMicros(); both classes
now have consistent API names.